The Mariners, who have already defeated Stamford AFC (3-2) and Scunthorpe United (4-0) in this season's competition, will be United's obstacle to reaching a first Senior Cup final since 2013.
United boss Adam Murray is again expected to shuffle his pack, with the big kick-off at Southport just two weeks away.
Goal flashes will be available on Twitter.
Match information, including use of the Town End for the first time in pre-season, is available here.